Field of the Invention
The present invention relates to a sheet binding mechanism for binding sheets accumulated in a bundle and to improvement of a pressure-binding mechanism for pressure-bonding a plurality of sheets using a pressurizing member for binding.
Description of the Related Art
Generally, as a binding device of such a type, there are known a binding mechanism that binds a sheet bundle accumulated in an aligned state with a staple and a stapleless binding mechanism that pressure-bonds a sheet bundle using a press mechanism to deform the sheets of the sheet bundle for binding. The sheet bundle bound by the above stapleless binding mechanism is bound without a metal binder and the sheets can thus be separated from each other easily.
For example, Jpn. Pat. Appin. Laid-Open Publication No. 2012-47940 discloses a mechanism that accumulates, in a bundle, sheets conveyed from an image forming device while aligning them and pressure-bonds the sheet bundle using a pair of upper and lower pressurizing members for binding. This document discloses a mechanism that drives a fixed-side pressurizing member with a concave-convex surface and a movable-side pressurizing member with a projecting-and-recessed surface to be engaged with the concave-convex surface of the fixed-side pressurizing member while connecting them through a motion transmission mechanism such as a cam connected to a drive motor.
Further, Jpn. Pat. Appin. Laid-Open Publication No. 2010-274623 discloses a mechanism that presses a pressurizing lever (upper tooth-shaped member 60A in this document) axially supported so as to be swingable against a fixed member (lower tooth-shaped member) using a drive cam connected to a drive motor (stepping motor). In this case, pressing force for pressing the sheets is about 100 kgf.